Computer networks such as the Internet allow users of computer systems to operate software applications that support the exchange of many types of information. As an example, a user of a portable computer system such as a laptop or handheld computerized device can operate a web browser software application as a client to communicate with web server computer systems on the Internet for access various types of information. The web server computer system may return web pages or other data to the client in response to receiving user requests for such data. Some web-based applications rely on the ability to obtain location information concerning a physical or geographical location of the client and/or server computer systems.
As a specific example, a user of a web browser may navigate to a web site on the world wide web that provides mapping information in order to obtain a geographical map that illustrates the surrounding area (i.e., the physical or geographical surroundings) of the user of the client computer system. To obtain location information related to the client, the web server may send a request to the web browser client prompting the user to enter location information concerning that user's specific location so that the mapping web server can return a map that corresponds to that users location. Upon receiving the location information entered by the user, the web server can access the mapping database to produce and serve a map back to the user's web browser identifying the geographical features relevant to user's location based on the location information provided by the user. As an example, the web server may prompt the user for a zip code in which that user is currently located. In response to receiving the zip code, the web server can serve a map of the town to which that the zip code is related.
Certain types of computer network applications can automatically retrieve location information concerning a location of a target device such as the client computer system in the example above. As another example, some computerized devices can be equipped with a Global Positioning System (GPS) receiver that monitors satellite transmissions of GPS satellites in order to perform a triangulation calculation to determine accurate latitude, longitude and altitude locations of the device that contains the GPS receiver. The computerized device may operate a software application that can respond to requests from a remote computer system for information concerning the GPS position of the computerized device. Such requests may be received, for example, over a wireless network. A specific example of such a device location tracking system exists in the shipping and freight industry. Mobile freight carriers such as tractor-trailer trucks can be equipped with the aforementioned computerized devices and GPS receivers. Such computer systems can report location information concerning the exact position of the freight carrier on route to delivery of freight to a particular destination.